1. EEE340Lecture 281 7-4: Potential functions Vector potential was introduced because Thus the Faraday’s law becomes i.e., Or (7.55) (7.56)

2. EEE340Lecture 282 This is allowed because Hence We wish to work with the two potentials V and, which have 4 unknowns, then Otherwise, one needs to solve with 6 unknowns. We begin with (7.57)

3. EEE340Lecture 283 Using i.e., (7-60)

4. EEE340Lecture 284 Applying the vector identity we obtain Let Lorentz gauge, the one has Non-homogeneous wave equation for, where velocity appear

5. EEE340Lecture 285 To obtain the wave equation for the scalar potential V, we begin with Or Hence (7-65)

6. EEE340Lecture 286 7-5: Electromagnetic Boundary Conditions E 1t =E 2t, always. B 1n =B 2n, always. For PEC, the conductor side H 2 =0, E 2 =0. (7.66b) (7.66c) (7.66a) (7.66d) (7.68)